diff -u --recursive gcc-10.3.0-vanilla/gcc/real.h gcc-10.3.0/gcc/real.h
--- gcc-10.3.0-vanilla/gcc/real.h	2021-04-08 06:56:28.561746620 -0500
+++ gcc-10.3.0/gcc/real.h	2022-05-18 17:04:32.076412174 -0500
@@ -77,8 +77,10 @@
    + (REAL_VALUE_TYPE_SIZE%HOST_BITS_PER_WIDE_INT ? 1 : 0)) /* round up */
 
 /* Verify the guess.  */
+#ifndef __LP64__
 extern char test_real_width
   [sizeof (REAL_VALUE_TYPE) <= REAL_WIDTH * sizeof (HOST_WIDE_INT) ? 1 : -1];
+#endif
 
 /* Calculate the format for CONST_DOUBLE.  We need as many slots as
    are necessary to overlay a REAL_VALUE_TYPE on them.  This could be
